1. Field of the Invention
The invention relates to a positioning apparatus and to a positioning method for transferring at least one electronic component, in particular a chip, from a first flat support to at least one predetermined location on a second flat support which extends parallel to the first support, comprising an ejection device for removing the component from the first support by means of an ejection movement.
2. Discussion of the Related Art
Usually, in order to produce smart labels, semiconductor chips are removed from a wafer held on a film which acts as first support by means of a removal device referred to as a flipper. In such flip-chip machines, the removed chip or dice is flipped by the flipper, that is to say is turned upside down, in order then to be transported by means of a pick-and-place system to a substrate which forms the second flat support and to be arranged thereon.
Since a relatively large distance (compared to the size of the chip) has to be covered between the site of removal from the film carrying the wafer and a predetermined location on the substrate, which comprises the bond contacts for bonding the chip to the substrate, a technically complicated flip-chip bonder machine is required in order to ensure precise positioning of the chip or dice on the substrate to be equipped therewith. Such machines have high manufacturing costs, increased maintenance requirements on account of their complicated design and a low throughput on account of the long transport paths for the flip-chips.
DE 197 34 317 A1 describes a bonder for bonding semiconductor chips to a predetermined location representing the bond position on a second support representing a substrate. In said device, firstly position data of the individual dice arranged within the expanded wafer are detected by means of a measuring device and stored. The expanded wafer representing the first support is then positioned with the chip to be removed above the predetermined location on the second support, which represents the position of the bond contacts of the chip to be bonded thereto. The back of the dice is then ejected by means of an ejection movement and thus detaches from the film by means of an ejection needle acting on the back of the dice from above. The dice is thus placed directly at the predetermined location on the substrate.
To this end, an operation of positioning the dice to be detached with respect to the predetermined location on the substrate takes place by means of the previously detected position data recorded by the measuring device. Since a displacement of the wafer and thus of the dice to be removed is necessary between detection of the positioning data by the measuring device and transfer of the dice from the wafer or film to the substrate, in order to be able to arrange the dice above the predetermined location on the substrate, there is a risk of intermediate displacement of the dice (the position data of which have already been detected) on the support film due to changing stresses in the support film. This means that precise positioning of the dice to be removed above the predetermined location on the substrate is no longer possible. This occurs in particular when using very small dice within very large wafers which are divided into a large number of dice, and when using very small bond contacts which are already arranged on the substrate in the predetermined location.
Moreover, in such transfer apparatuses, there is no direct detection of the position data of the bond contacts at the location at which the bonding process is to be carried out. Rather, indirect one-dimensional positioning of the bond contacts is carried out by means of drive rollers by positioning the strip-shaped substrate on which the bond contacts are arranged. Due to existing material tolerances and position errors, this results in positioning errors in respect of the positioning of the predetermined location.
Furthermore, the described apparatus does not have a positioning device for positioning the ejection device with respect to the position of the dice to be removed and the predetermined location. This may also be a possible source of error for insufficiently precise positioning of the predetermined location with respect to the dice to be removed and the ejection device, and thus for precise arrangement of the dice on the bond contacts.